java.lang.NullPointerException
        at android.widget.Switch.jumpDrawablesToCurrentState(Switch.java:825)
        at android.view.ViewGroup.jumpDrawablesToCurrentState(ViewGroup.java:5158)
        at android.view.ViewGroup.jumpDrawablesToCurrentState(ViewGroup.java:5158)
        at android.view.ViewGroup.jumpDrawablesToCurrentState(ViewGroup.java:5158)
        at android.view.ViewGroup.jumpDrawablesToCurrentState(ViewGroup.java:5158)
        at android.widget.FrameLayout.jumpDrawablesToCurrentState(FrameLayout.java:189)
        at android.view.ViewGroup.jumpDrawablesToCurrentState(ViewGroup.java:5158)
        at android.view.ViewGroup.jumpDrawablesToCurrentState(ViewGroup.java:5158)
        at android.widget.FrameLayout.jumpDrawablesToCurrentState(FrameLayout.java:189)
        at android.view.ViewGroup.jumpDrawablesToCurrentState(ViewGroup.java:5158)
        at android.view.ViewGroup.jumpDrawablesToCurrentState(ViewGroup.java:5158)
        at android.widget.FrameLayout.jumpDrawablesToCurrentState(FrameLayout.java:189)
        at android.view.View.onAttachedToWindow(View.java:11583)
        at com.android.internal.policy.impl.PhoneWindow$DecorView.onAttachedToWindow(PhoneWindow.java:2463)
        at android.view.View.dispatchAttachedToWindow(View.java:11960)
        at android.view.ViewGroup.dispatchAttachedToWindow(ViewGroup.java:2415)
        at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1195)
        at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:992)
        at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:4355)
        at android.view.Choreographer$CallbackRecord.run(Choreographer.java:749)
        at android.view.Choreographer.doCallbacks(Choreographer.java:562)
        at android.view.Choreographer.doFrame(Choreographer.java:532)
        at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:735)
        at android.os.Handler.handleCallback(Handler.java:728)
        at android.os.Handler.dispatchMessage(Handler.java:92)
        at android.os.Looper.loop(Looper.java:138)
        at android.app.ActivityThread.main(ActivityThread.java:5089)
        at java.lang.reflect.Method.invokeNative(Native Method)
        at java.lang.reflect.Method.invoke(Method.java:511)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
        at dalvik.system.NativeStart.main(Native Method)

这个异常，是因为我们使用Switch这个控制的时候，不规范导致，我们会这样写：（这个在高版本android上不会出错）

            <Switch
                android:id="@+id/autoConnect"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_alignParentEnd="true"
                android:background="@drawable/cb_switch_blue"
                android:text=""
                android:textOff=""
                android:textOn=""
                android:thumb="@null"
                android:track="@null" />

正是其中的那个null导致了这个问题，解决办法是，不要用null，如下使用透明代替

            <Switch
                android:id="@+id/autoConnect"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_alignParentEnd="true"
                android:background="@drawable/cb_switch_blue"
                android:text=""
                android:textOff=""
                android:textOn=""
                android:thumb="@android:color/transparent"
                android:track="@android:color/transparent" />